WO2003000600A1

WO2003000600A1 - System for purifying waste water originating from dumps (leachates) by means of alkalinisation and ozonisation

Info

Publication number: WO2003000600A1
Application number: PCT/ES2002/000309
Authority: WO
Inventors: José TORO GALVEZ
Original assignee: Toro Galvez Jose
Priority date: 2001-06-25
Filing date: 2002-06-25
Publication date: 2003-01-03
Also published as: ES2183723A1; ES2183723B1

Abstract

The invention relates to a system for purifying waste water originating from dumps comprising the following steps: 1) coagulation-flocculation; 2) alkalinisation with sodium hydroxide; 3) pressurised air injection and filtration in parallel; 4) filtration with sand bed, nylon and active carbon; 5) ozonisation; 6) filtration with sand bed, nylon, diatoms and active carbon; 7) reverse osmosis. Said system can be used to produce completely disinfected, clear, odourless water that complies with all legislative standards. Moreover, said system is economical, fast, effective, easy to manage and perfectly compatible with the environment and persons.

Description

WASTE WATER CLEANING SYSTEM FROM DRAWERS (LIXIVIATES) THROUGH ALKALINATION AND OZONIZATION

Wastewater purification system from garbage dumps (leachate) through which I get a very high degree of elimination of toxic and harmful substances that integrate it. Economic system, fast, easy to handle, effective and compatible with the environment.

BACKGROUND.

Aqueous waste from landfills is "AGUAS NEGRAS

LOADED WITH VERY ORGANIC AND INORGANIC PARTICLES

TOXIC "impossible to be discharged into public channels or be reused in any other way possible, because by environmental legal provisions are incompatible with the environment, making it impossible to develop the life of any type of organism and considerably affecting the environment that circumscribes them .

This type of residue is characterized by having intrinsic parameters such as a DB05 of 60-70 g 1, COD of 80-120 g / 1, electrical condutivity greater than 20,000 S / cm, in addition to a large amount of salts, fats, ions and heavy metals.

Therefore, the need for treatment and purification is obvious.

The current solutions to achieve sufficient parameters for the law to authorize its discharge are void.

The biological treatment for, through the use of microorganisms, to degrade the pollutants and to innocuolize them has not achieved optimal or reliable results, since this type of residue has inhibitory substances that affect its basal metabolism, preventing its development and therefore, the ability to oxidation of the pathogenic substances responsible for their toxicity.

The purification system by alkalization and ozonation is a physical-chemical system in its entirety that lacks any biological phase that can be affected by this type of substances.

In what I explain below I demonstrate the achievement of the parameters of Poured appropriate to those required by current law through a new and effective system whose purpose I request the patent be authorized.

DESCRIPTION OF THE INVENTION The wastewater purification system from garbage dumps (leachate) by alkalization and ozonation is based on the following successive stages: I ^a Stage of coagulation-flocculation with alumina sulfate (Figure 1.a): In this first stage called coagulation-flocculation subject this wastewater (leachate) to a chemical coagulation-flocculation process of particles that exist in suspension by directly adding 50% liquid alumina sulfate residue, AL> (Sθ4) 3. The dosage of alumina sulfate will vary depending on the value of suspended solids that the residue possesses, the dosage ranges being as follows:

SUSPENSION SOLIDS (mg / l): 800-6000 ALUMIN SULFATE (ml / 1): 5-20

After this addition and with slow stirring, two phases are formed, a yellowish liquid (Fig. 1) and a solid brown (Fig. 1). I separate these phases by a conventional decanting system and obtain the two separate phases. The objective of this stage is to separate colloidal particles that are in suspension from the crude residue by forming, through the complexing capacity of alumina sulfate, large clots and flocs that allow their separation by sedimentation and settling. 2 alkalization step and removing fat with sodium hydroxide (Figure 1.b: It involves the addition of liquid sodium hydroxide at 50% (NaOH) directly to the liquid waste yellowish (Fig.l.al) result in separation occurred the previous step The dose of this reagent that I add to the residue depends on the ph that it has, since the objective is to increase the value of the same to a value between 10 and 13. The dosage range of sodium hydroxide is from 10 to 30 milliliters per liter of waste.With this stage I get:

-Remove fat from the residue by forming a paste that looks soapy and orange in color (Fig.l.b2) that is formed due to the coagulation capacity of sodium hydroxide when dissolved in the residue, since Its strong base character causes the chemical equilibrium NaOH Na + OH to move completely towards the formation of Na and OH, which will be the ions responsible for coagulating colloids and esterifying the fatty particles that are still in suspension, forming an orange soapy paste that precipitates (Fig.l.b2), and that will be eliminated by a conventional decanting process, and a yellowish liquid phase (Fig.l.bl) that will pass to the later phase.

3 ^a Pressurized air injection stage (Figure lc) and parallel filtration (Figure ld): After separating the two phases obtained in the alkalization stage, I remove a yellowish liquid phase (Fig. L .bl), with a value of ph between 10-13, which I will put in contact with atmospheric air (20m3 of atmospheric air / hour per m3 of waste, for 12 hours, with a bubble path * of 4 meters vertically) by means of an air injector system under pressure (Fig.l. el) and in parallel a nylon filter (Fig.l. d) in which the retained solid will be sent to the first stage (Fig.l.dl), after washing and rinsing the same. With this stage I get:

-Oxidate and filter at the same time particles that are still in suspension and dissolved, in addition I get an elimination of ions, which oxidize with atmospheric O2 form insoluble salts and colloids that precipitate and are retained in the nylon fiber in the filtration process: The objective of this filtration is in parallel is that the salts and colloids are removed as they are formed. -Eliminate volatile particles of the medium such as ammonia, methane, hydrogen, nitrogen, e.t.c ..., since the bubbles that are formed when injecting the pressurized air produce a drag of them from the bed of the residue to the atmosphere. (These gases can be collected in a distillation hood and reused).

* The bubble size must be less than mm.

4 ^to Step filtration sand bed, nylon v active carbon (Figure l.eV. submit the liquid ^to get the three stage filtration sand bed (Fig.l. el), nylon (Fig.l e2) and activated carbon (Fig.l. e3) I get two phases already separated, one solid retained in the filters (Fig.l. e4) and another liquid (Fig.l. e5) that goes on to the next phase of ozonation

The solid phase will go back to the first phase in the process of washing and rinsing the filters. Stage 5 invección ozone (Figure lf):

The liquid phase obtained in step 4 (Fig.l. e5) is now subjected to an injection of ozone gas through a system of generating ozone gas (θ3) pressure

(Fig.l.fl) and porous diffusers to facilitate contact between gas and liquid in question.

The effective dose is in the range of 200-500 g of OJm3 of residue, which depends on the COD value you have before starting this stage, which will be

15-25 g 1 respectively.

As in the previous stage of injection of pressurized air, the bubble must have a size smaller than lmm (this is achieved through a system of porous diffusers) and must cover a vertical space of 4 meters, so that the contact between ozone and the liquid is more effective.

Gaseous ozone acts as a strong oxidizing agent that destroys and oxidizes the organic and inorganic particles that are still part of this liquid, a chemical process called ozonolysis. The result of this oxidation is as follows:

-Blanks and removes any trace of color that remains in the liquid making it colorless.

-Eliminates odorous particles, making it, therefore, odorless.

-Disinfects and therefore eliminates any type of microorganism, be it bacteria, fungus, algae or virus found in the residue.

6 ^a Filtering stage in sand, nylon, diatoms and activated carbon (Figure lg):

The liquid obtained in the ozonation stage (Fig. 1 2) is subjected to sand bed filtration (Fig.l.gl), nylon (Fig.l.g2), diatoms (Fig.l.g3) and active carbon (

Fig.l.g4), obtaining a colorless and odorless liquid phase (Fig.l.g5) and a solid one (Fig.l. g6) that will be retained in the filters and will go back to the first stage of the system in the process of washing and rinsing the filters, in the same way as in the

4 ^to stage.

The liquid phase will go to the next stage.

7 ^a Reverse osmosis stage (Figure lh): The colorless liquid phase is subjected to a process of fine tuning and removal of dissolved particles by a reverse osmosis process.

After this last stage I get two liquid phases, a small residual phase loaded with salts (Figure li) and another colorless one (Figure lj) whose parameters are within those that the law marks to be able to be spilled to any type of public channel.

Claims

CLAIMS.

1. Wastewater purification system from garbage dumps (leachate) by alkalization and ozonation, characterized by having the following stages (and in the order that I list them): I ^a Coagulation-flocculation stage with alumina sulfate.

2 alkalization step and removing fat with sodium hydroxide. 3 ^a Stage of injection of pressurized air and parallel filtration. 4 ^a Filtration stage in sand bed, nylon and activated carbon. 5 ozonation stage. ^a Filtration stage in sand bed, nylon, diatoms and activated carbon. ^a Reverse osmosis stage.